Various types of the so-called flat-panel displays are well known in the art and include, for example, plasma discharge panels, cathodoluminescent panels, electroluminescent panels, liquid-crystal panels, electrophoretic panels and electrochromic panels. Although these flat-panel display systems are substantially different from one another in construction and method of operation, they have in the past all been contained in substantially similar structural packages, namely the electrode structure is sandwiched between a pair of glass panels or between one glass panel and a rigid rear cover member. While the basic panel construction is suitable for use with relatively small panels, when larger panels of, for example, ten to one hundred square feet are required, the weight, cost and stresses in the panels make such construction impractical.
Of the above-mentioned types of displays, the plasma discharge and cathodoluminescent types require a very-low-pressure, controlled atmosphere wherefor the space or cavity within the panel must be sealed from the atmosphere and evacuated. When this cavity between the front and rear panels of a prior art flat-panel display is evacuated, the central areas of the panels are pressed by atmospheric pressure into the cavity, which causes high tensile stresses to be established within the panels. As a consequence, since at least one of the panels must be glass and thus low in tensil strength, large displays cannot be made in this way unless inordinately thick glass panels are used.